The two operations, deletion and contraction of an edge, on multigraphs directly lead to the Tutte polynomial which satisfies a universal problem. As observed by Brylawski [8] in terms of order relations, these operations may be interpreted as a particular instance of a general theory which involves universal invariants like the Tutte polynomial, and a universal group, called the Tutte-Grothend...

In this paper, we prove decidability properties and new results on the position of the family of languages generated by (circular) splicing systems within the Chomsky hierarchy. The two main results of the paper are the following. First, we show that it is decidable, given a circular splicing language and a regular language, whether they are equal. Second, we prove the language generated by an ...

Behaviour of systems is described by formal languages: the sets of all sequences of actions. Regarding abstraction, alphabetic language homomorphisms areion, alphabetic language homomorphisms are used to compute abstract behaviours. To avoid loss of important information when moving to the abstract level, abstracting homomorphisms have to satisfy a certain property called simplicity on the conc...

Word recognition develops with such remarkable speed that, by the end of eighth grade, we expect children learning to read English to know and recognize over 80,000 words (Adams, 1990). At a basic level, beginning readers must establish a system of mappings or correspondences between the letters or graphemes of written words and the phonemes of spoken words (Ehri, 1992), and it is generally tho...

This article discusses the relationship between spelling mistakes and writing levels based on theory of psychogenesis analysis texts produced by literate children, youths adults. Stemming from idea that literacy process is evolutionary that, if not properly developed for orthographic alphabetic level, it will result in fact individuals, albeit literate, carry out mistakes, example, cases intern...

Alphabetic trees are trees without any internal edge crossing despite an imposed total order on their leaf nodes This paper presents a systematic procedure for generating all alphabetic trees on a given number of leaf nodes under bounded degree and or bounded height criteria The number of such trees is calculated and used to derive upper bounds on the complexity of the corresponding alphabetic ...

Título: Facilitadores del proceso de aprendizaje de la escritura en las primeras edades. Resumen: El estudio del aprendizaje de la escritura en las primeras edades ha sido objeto de numerosas investigaciones en los últimos años. Actualmente se sabe que en las lenguas de escritura alfabética como la nuestra, aprender a escribir requiere tanto del conocimiento alfabético como de la toma de concie...